Power window regulators (NA and NB)
Power window regulators wear out on the NA and NB, and the usual failure is a broken cable or a worn slider while the motor still works. This page lists the replacements sellers offer and what owners said in a 2024 thread. It is not a repair guide.
How to read it. Seller descriptions are from their own pages, and owner accounts from Miata.net forum threads, read on 1 October 2026 and dated below. Owners disagree, and none of it was tested by me. There are no prices on this page.
Replacements
| Seller | What it says it offers | Fits (as stated) |
|---|---|---|
| Moss Miata | brand new regulators with a new motor, made for the NA and NB, which it presents as cheaper than a factory regulator without a motor; for left or right. It says it tested them on its own cars. 12-month warranty, with the purchase invoice and failure documentation needed for a claim | NA and NB, 1990-2005 |
| Treasure Coast Miata | a rebuilt assembly: a tested used motor on a new Mazda OEM regulator with Mazda hardware, pre-assembled. For the driver side you send in your motor to be tested first; the passenger side usually needs no core. Made to order in 1 to 2 weeks; the page showed limited supply | NA, 1990-97 |
Moss also lists regulators by I.L. Motorsports, factory-style motors and a manual regulator, and MiataSource a manual regulator, per search results; I did not open them.
What owners say
From "Window Regulator Broken Cable Fix?" (July 2024, 1992 NA, driver's door):
- The failure. The owner's motor still worked but the cable had snapped. A poster who gave a detailed reply said the first two sliders on the glass are fine and the third is what breaks; keep its screw and plates for the new part, buy two (one per door) and do not expect the other door to be much better. Another suggested checking the cable has really snapped, and looking at the bottom of both doors for rust.
- Repair or replace. Several owners suggested a new regulator with the old motor transferred. One sent his motor to Treasure Coast, which returned a ready-to-fit regulator, and said his driver's window now moves in about half the time of the passenger side. The cables are bicycle-type Bowden cable; a repair means cutting to length and fashioning a new end, which a bike shop might do. One poster suggested an electric replacement regulator-with-motor from an aftermarket supplier.
- Lubricant and cleaning. The detailed reply said white lithium grease is the wrong lubricant, because it hardens, and recommended wheel grease or Shin-Etsu silicone grease on the rubber-to-glass surfaces, and cleaning the front glass guide and glass thoroughly. Another poster said acetone should only go on glass or unpainted metal; the first said it is harmless on most surfaces for him and alcohol also works.
- The plastic moisture barrier. One owner had found the barrier left out. Posters said it protects the fiberboard door card from water, and that making your own from plastic sheeting is easy.
- Door cards. Posters suggested hardening worn clip keyholes in the fiberboard with thin cyanoacrylate glue, and painting the card with clear polyurethane to guard against water damage.
- Manual windows. One poster recommended swapping manual windows for power, because cranking a window while driving a quick-steering Miata is risky.
Not covered yet
- The regulator sliders and window glass hardware sold separately, and Mazda's part numbers; the thread says Mazda changed its policy on selling them separately, which I could not confirm.
- NC and ND window parts, and other electrical parts such as switches and relays.
© 2026 Fischer Interactive LLC. Written for the Ref Sensor app's Miata users. The seller's page is the authority.